Knut dahl. 



cement of rational researches as to the relation between young 

 salmon and sea trout in our waters. The storthing voted the 

 necessary means, wich also during the whole progress of the 

 research have been liberally granted. 



During the 4 years from 1898 to 1902 I have under- 

 taken quite a comprehensive series of investigations concerning 

 the distribution of different stages of salmon and seatrout in 

 our waters in connection with studies on their specific charac- 

 ters and biological differences. 



In the following chapters I propose to give an account of 

 these investigations and their results, which, according to my 

 opinion, not only throw new hght on the questions mentioned 

 above, but also have importance to other features in legisla- 

 tion relating to salmon and trout-fisheries. 



Chapter I. 

 The methods and implements of the investigations. 



Any investigator wishfull of forming an independent opinion 

 based on observation, will to my thinking, on reading the large 

 mass of literature relating to the problems shortly mentioned in 

 the introduction, find a lack of systematically continued resear- 

 ches founded on direct observations in nature concerning the 

 species in question, their wanderings or habitats in different 

 stages of life. 



From the abovementioned literature it transpires, as far as 

 I have been able to see, that those naturalists, who have treated 

 salmon and trout, have got the essential proportion of their ma- 

 terial from museums. Certainly they have also made indepen- 

 dent collections in nature, but these seem in most cases to have 

 had a casual caracter and been merely supplementary. Among 

 those investigators, who have gained the best knowledge on 

 these species, there is hardly one, who has had the opportunity 

 of undertaking numerous independent fishing experiments over 



